The present invention relates to a control apparatus of an automatic transmission, which controls engagement/disengagement of an engagement part and is capable of maintaining an input revolution speed of the engagement part at an appropriate revolution speed that depends on power-ON/OFF states, to achieve a target input revolution speed of the engagement part at least according to the power-ON/OFF states.
As a control apparatus of the automatic transmission, for example, a Japanese Patent Provisional Publication No. 2007-225048 (hereinafter is referred to as “JP2007-225048”) discloses a control apparatus of the automatic transmission. In JP2007-225048, a difference between an input revolution speed when engaged and an actual input revolution speed of an engagement part of a lock-up clutch and a difference between the input revolution speed when engaged and a target input revolution speed of the same engagement part, are compared. Then, by changing a capacity (an engagement fluid pressure or a disengagement fluid pressure) of the engagement part in accordance with a magnitude relationship between these differences, the clutch is slip-engaged while maintaining the input revolution speed of the target.